package ru.myrtle.umf.util;

import java.util.HashMap;
import java.util.Map;

import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

class UXMLStreamWriter implements XMLStreamWriter {

    private static final int INDENT = 4;

    private static final String INDENT_CHAR = " ";
    private static final String LINEFEED_CHAR = "\n";

    private final XMLStreamWriter writer;
    private final Map<Integer, Boolean> hasChildElement =
            new HashMap<Integer, Boolean>();

    private int depth = 0;

    public UXMLStreamWriter(XMLStreamWriter writer) {
        this.writer = writer;
    }

    /*
     *
     */

    String repeat(int times, String string) {
        final StringBuilder sb = new StringBuilder();

        for (int i = 0; i < times; i++) {
            sb.append(string);
        }
        
        return sb.toString();
    }

    void indent() {
        depth += INDENT;
    }

    void outdent() {
        depth -= INDENT;
    }

    void beforeWriteStartElement() throws XMLStreamException {
        // update state of parent node
        if (depth > 0) {
            hasChildElement.put(depth - INDENT, true);
        }

        // reset state of current node
        hasChildElement.put(depth, false);

        // indent for current depth
        writer.writeCharacters(LINEFEED_CHAR);
        writer.writeCharacters(
                repeat(depth, INDENT_CHAR)
        );

        indent();
    }

    void beforeWriteEmptyElement() throws XMLStreamException {
        // update state of parent node
        if (depth > 0) {
            hasChildElement.put(depth - 1, true);
        }

        // indent for current depth
        writer.writeCharacters(LINEFEED_CHAR);
        writer.writeCharacters(
                repeat(depth, INDENT_CHAR)
        );
    }

    void beforeWriteEndElement() throws XMLStreamException {
        outdent();

        if (hasChildElement.get(depth)) {
            writer.writeCharacters(LINEFEED_CHAR);
            writer.writeCharacters(
                    repeat(depth, INDENT_CHAR)
            );
        }
    }

    /*
     *
     */

    @Override
    public void writeStartElement(String localName) throws XMLStreamException {
        beforeWriteStartElement();

        writer.writeStartElement(
                localName
        );
    }

    @Override
    public void writeStartElement(String namespaceURI, String localName) throws XMLStreamException {
        beforeWriteStartElement();

        writer.writeStartElement(
                namespaceURI, localName
        );
    }

    @Override
    public void writeStartElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {
        beforeWriteStartElement();

        writer.writeStartElement(
                prefix, localName, namespaceURI
        );
    }

    @Override
    public void writeEmptyElement(String namespaceURI, String localName) throws XMLStreamException {
        beforeWriteEmptyElement();

        writer.writeEmptyElement(
                namespaceURI, localName
        );
    }

    @Override
    public void writeEmptyElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {
        beforeWriteEmptyElement();

        writer.writeEmptyElement(
                prefix, localName, namespaceURI
        );
    }

    @Override
    public void writeEmptyElement(String localName) throws XMLStreamException {
        beforeWriteEmptyElement();

        writer.writeEmptyElement(
                localName
        );
    }

    @Override
    public void writeEndElement() throws XMLStreamException {
        beforeWriteEndElement();

        writer.writeEndElement();
    }

    @Override
    public void writeEndDocument() throws XMLStreamException {
        writer.writeEndDocument();
    }

    @Override
    public void close() throws XMLStreamException {
        writer.close();
    }

    @Override
    public void flush() throws XMLStreamException {
        writer.flush();
    }

    @Override
    public void writeAttribute(String localName, String value) throws XMLStreamException {
        writer.writeAttribute(localName, value);
    }

    @Override
    public void writeAttribute(String prefix, String namespaceURI, String localName, String value) throws XMLStreamException {
        writer.writeAttribute(prefix, namespaceURI, localName, value);
    }

    @Override
    public void writeAttribute(String namespaceURI, String localName, String value) throws XMLStreamException {
        writer.writeAttribute(namespaceURI, localName, value);
    }

    @Override
    public void writeNamespace(String prefix, String namespaceURI) throws XMLStreamException {
        writer.writeNamespace(prefix, namespaceURI);
    }

    @Override
    public void writeDefaultNamespace(String namespaceURI) throws XMLStreamException {
        writer.writeDefaultNamespace(namespaceURI);
    }

    @Override
    public void writeComment(String data) throws XMLStreamException {
        writer.writeComment(data);
    }

    @Override
    public void writeProcessingInstruction(String target) throws XMLStreamException {
        writer.writeProcessingInstruction(target);
    }

    @Override
    public void writeProcessingInstruction(String target, String data) throws XMLStreamException {
        writer.writeProcessingInstruction(target, data);
    }

    @Override
    public void writeCData(String data) throws XMLStreamException {
        writer.writeCData(data);
    }

    @Override
    public void writeDTD(String dtd) throws XMLStreamException {
        writer.writeDTD(dtd);
    }

    @Override
    public void writeEntityRef(String name) throws XMLStreamException {
        writer.writeEntityRef(name);
    }

    @Override
    public void writeStartDocument() throws XMLStreamException {
        writer.writeStartDocument();
    }

    @Override
    public void writeStartDocument(String version) throws XMLStreamException {
        writer.writeStartDocument(version);
    }

    @Override
    public void writeStartDocument(String encoding, String version) throws XMLStreamException {
        writer.writeStartDocument(encoding, version);
    }

    @Override
    public void writeCharacters(String text) throws XMLStreamException {
        writer.writeCharacters(text);
    }

    @Override
    public void writeCharacters(char[] text, int start, int len) throws XMLStreamException {
        writer.writeCharacters(text, start, len);
    }

    @Override
    public String getPrefix(String uri) throws XMLStreamException {
        return writer.getPrefix(uri);
    }

    @Override
    public void setPrefix(String prefix, String uri) throws XMLStreamException {
        writer.setPrefix(prefix, uri);
    }

    @Override
    public void setDefaultNamespace(String uri) throws XMLStreamException {
        writer.setDefaultNamespace(uri);
    }

    @Override
    public void setNamespaceContext(NamespaceContext context) throws XMLStreamException {
        writer.setNamespaceContext(context);
    }

    @Override
    public NamespaceContext getNamespaceContext() {
        return writer.getNamespaceContext();
    }

    @Override
    public Object getProperty(String name) throws IllegalArgumentException {
        return writer.getProperty(name);
    }
}
